44. Dumb at its concept.

First, visual reaction time could only be correlated with intelligence in infants and toddlers. By adulthood, a lot of factors can effect it, most of which have nothing to do with intelligence. How well do you think Stephen Hawking would score on this test?

Second, the people getting tested would have been the ones the testers would have found easier access to: educated people. This automatically biases the tests.

Third, the testers themselves, especially Sir Francis Galton, had their own pet theories and were biased. Galton was the first eugenicist, in fact he coined the term.

Fourth, and this one was mentioned, the equipment was far cruder.

This is not to say people aren't getting dumber, just to say this test is the equivalent of consulting tea leaves about it.